2017-02-28 85 views
1

我试图创建一个递归方法来创建一个菜单。 我想实现的菜单显示儿童的孩子等。 我已经调试过代码,一直到“最小的孩子”。递归方法不会循环儿童儿童

public string GetMenu(Node currentPage) 
    { 
     StringWriter stringWriter = new StringWriter(); 
     using (HtmlTextWriter writer = new HtmlTextWriter(stringWriter)) 
     { 

     foreach (var item in currentPage.ChildrenAsList) 
     { 
      writer.RenderBeginTag(HtmlTextWriterTag.Li); 
      writer.AddAttribute(HtmlTextWriterAttribute.Href, item.Url); 
      writer.RenderBeginTag(HtmlTextWriterTag.A); 
      writer.Write(item.Name); 


      if (item.ChildrenAsList.Any()) 
      { 
       writer.RenderBeginTag(HtmlTextWriterTag.Ul); 
       GetMenu(new Node(item.Id)); 
       writer.RenderEndTag(); 
      } 
      writer.RenderEndTag(); 
      writer.RenderEndTag(); 
     } 
    } 
    return stringWriter.ToString(); 
} 

这种方法给输出:

<ul class="nav nav-sidebar"> 

    <li> 
    <a href="/artikelsida001/">Artikelsida001 
    <ul> 

    </ul> 
    </a></li> 
    <li><a href="/patrikartikelsida/">PatrikArtikelsida 
    <ul> 

    </ul> 
    </a></li> 
    <li><a href="/en-testsida/">En testsida</a></li> 
    </ul> 
+2

我想你忘了问一个问题。 BUt我怀疑它与你对GetMenu(新节点(item.Id))的回应有关。' – Jamiec

+0

对不起@MongZhu,这是我在这里的第一篇文章,所以我重写了几次,使它成为好。显然它没有那么好。无论如何Jon已经解决了,谢谢! :) –

+0

@PatrikJansson别担心。您可以使用您帖子下方的[编辑按钮](http://stackoverflow.com/posts/42509835/edit)将信息添加到您的帖子中。它不是刻在石头上)幸运 –

回答

4

每次调用GetMenu的时候,你要创建一个新的StringWriter - 但你忽略了从递归调用的返回值。最简单的修复很可能是将其改为:

public string GetMenu(Node currentPage) 
{ 
    var stringWriter = new StringWriter(); 
    using (var htmlWriter = new HtmlTextWriter(stringWriter)) 
    { 
     RenderMenu(currentPage, writer); 
    } 
    return stringWriter.ToString(); 
} 

private void RenderMenu(Node node, HtmlTextWriter writer) 
{ 
    // Mostly copied from the code in the question... 
    foreach (var item in currentPage.ChildrenAsList) 
    { 
     writer.RenderBeginTag(HtmlTextWriterTag.Li); 
     writer.AddAttribute(HtmlTextWriterAttribute.Href, item.Url); 
     writer.RenderBeginTag(HtmlTextWriterTag.A); 
     writer.Write(item.Name); 

     if (item.ChildrenAsList.Any()) 
     { 
      writer.RenderBeginTag(HtmlTextWriterTag.Ul); 
      // Note the change here 
      RenderMenu(new Node(item.Id), writer)); 
      writer.RenderEndTag(); 
     } 
     writer.RenderEndTag(); 
     writer.RenderEndTag(); 
    } 
} 

注意递归现在怎么调用RenderMenu同一位作家

+0

啊,谢谢,这解决了问题! –